摘要:

AbstractDevelopment trends in catalytic fluid reactions. Problems associated with raw materials, energy, and the environment have had many repercussions on the industrial development of catalytic processes. Apart from efforts to increase the use of coal‐based feedstock such as synthesis gas and methanol, particular attention is focussed upon improvements in the selectivity of industrial reactions. There appears to be a reversal of direction in the choice of phase: proven homogeneous catalysts are being heterogenized, and heterogeneous catalysts are being employed in homogeneous or liquid form. Other typical features are increased efforts to replace conventional multistep syntheses by direct syntheses, and high pressure syntheses by medium or low pressure syntheses. Finally, measures designed to regenerate or conserve catalytic activity and selectivity are becoming more and more importan

ISSN:0009-286X    

DOI:10.1002/cite.330540102

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractDesign of ejectors for single‐phase material systems. The principal design data of self‐priming jet devices are presented. A theoretical design model is first discussed which provides a good description of the experimental results reported in the literature. Application of this model requires introduction of empirical parameters which depend solely upon geometry and have been determined for various ejector types from experimental results. An energetic comparison permits estimation of the influence of the individual geometrical parameters on the efficiency. This leads to the concept of an energetically favourable device whose efficiency and suction characteristics are given over a wide range of through

ISSN:0009-286X    

DOI:10.1002/cite.330540103

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractMaintenance‐favourable design of industrial plant. A study by the German Maintenance Committee proves that maintenance costs in the Federal Republic in 1977 amounted to 123 × 109DM, of which 30 × 109DM were accounted for by manufacturing industry and more than 5 × 109DM by the chemical industry. Over 50% of subsequent damage costs are caused in the planning and manufacture phase. These sources of damage become manifest during later use and damage and secondary damage costs are incurred by the user. An appeal therefore goes out to plant manufacturers, users, and maintenance staff to cooperate in reducing the sources of damage. An important basis for such a move is the collection and exchange of data, utilization of data pools, and systematic analysis for determination of weak points at the planning and construction stage. Since maintenance costs, as one of the four operational cost factors (material, personnel, energy, and maintenance costs), show an increasing tendency with progressive automation there is a continuiing need for a cost or profit center for plant engineering or planned mainten

ISSN:0009-286X    

DOI:10.1002/cite.330540104

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractFinishing of metals by ion beams. For many years ion beams have been used for doping semiconductors. Recently more and more interest has been shown in them as a method for the finishing of metals. The insertion of an alloying element as an energetic ion into a 0.1 to 1 μm thick surface layer of a metal instead of bulk alloying is interesting, especially with respect to a future shortage of resources. In addition, the ion beam techniques (ion implantation and ion beam mixing) provide the possibility of implanting any element in nearly any substrate. This may often lead even to metastable or amorphous surface structures. In this paper the ion beam techniques are described and the resulting materials are outlined. The possibilities for applications in different fields such as corrosion, mechanical surface properties (tribology), and catalysis are illustrated with examples. They range from pure basic science and applied science to potential procedures to be used in industrial production

ISSN:0009-286X    

DOI:10.1002/cite.330540105

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540106

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractStudy of heterogeneous catalysts by modern surface analysis methods. The past decade has been one of tempestuous development in methods of surface analysis as a result of significant improvements of vacuum techniques and electronic components. The principal methods available for studying the chemical composition of catalysts are ESCA, Auger spectroscopy, ISS (ion scattering spectroscopy), and SIMS (secondary ion mass spectrometry). The “classical scanning microscope” and various “micro‐range” analyzers, e. g. the scanning Auger microscope, permit elucidation of catalyst surface structures. Advantages and drawbacks of the various methods are presented with the aid of selected examples and the limits of the analysis of industrial catalysts are

ISSN:0009-286X    

DOI:10.1002/cite.330540107

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540108

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractA critical view of the hydrogen economy. The goal of the hydrogen economy is to replace electrical energy, petroleum products, and natural gas wherever feasible by hydrogen as secondary energy. Apart from the coal the only primary energy source which be available in the near future will be nuclear energy, preferentially for supplying process heat for coal gasification (high temperature reactor). There will hardly be a future for thermochemical cyclic processes for cleavage of water; development of electrolytic process utilizing electrical energy from nuclear reactors appears technically and economically more promising. Exploitation of solar energy for generation of hydrogen appears unlikely in this century. The original concept of the hydrogen economy was associated with the discovery of hydrides of intermetallic compounds which are suitable for reversible storage of hydrogen. During the ensuing 15 years since the pioneering studies on this topic extensive detailed knowledge has accrued about the thermodynamic behaviour of hydride storage systems, their lattice structure, and the uptake and release of hydrogen. In any case, the hydrogen economy will be expensive with regard to both development and the necessary investment in this application.

ISSN:0009-286X    

DOI:10.1002/cite.330540109

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540110

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540111

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY